Cops Think Murray Shacked Up with Baby Mama

9/22/2009 6:48 PM PDT BY TMZ STAFF

Nicole Alvarez, the mother of Dr. Murray's 7th child, has not been cooperative with LAPD detectives. We have already reported that we have heard Dr. Murray was living with Alvarez during the time he was supposedly staying with Jackson. Law enforcement sources tell us they believe Dr. Murray was living with Alvarez but have not been able to confirm it.

If Dr. Murray was regularly around Alvarez during that critical time, she may have information that could be highly relevant to the investigation.

Our sources say there is nothing specific they're after when Alvarez goes before the Grand Jury. As one source put it, it's more of an "exploratory" exercise.